Naphthalimide Trifluoroacetyl Acetonate: A Hydrazine-Selective Chemodosimetric Sensor

The trifluoroacetyl acetonate naphthalimide derivative 1 has been synthesized in good yield. In acetonitrile solution, compound 1 reacts selectively with hydrazine (NH2NH2) to give a five-membered ring. This leads to OFF-ON fluorescence with a maximum intensity at 501 nm as well as easily discernible color changes. Based on a readily discernible and reproducible 3.9% change in overall fluorescence intensity, the limit of detection for 1 is 3.2 ppb (0.1 mu M), which is below the accepted limit for hydrazine set by the U.S. Environmental Protection Agency (EPA). Compound 1 is selective for hydrazine over other amines, including NH4OH, NH2OH, ethylenediamine, methylamine, n-butylamine, piperazine, dimethylamine, triethylamine, pyridine, and is not perturbed by environmentally abundant metal ions. When supported on glass-backed silica gel TLC plates, compound 1 acts as a fluorimetric and colorimetric probe for hydrazine vapor at a partial pressure of 9.0 mm Hg, with selectivity over other potentially interfering volatile analytes, including ammonia, methylamine, n-butylamine, formaldehyde, acetaldehyde, H2O2, HCl, and CO2 being observed. Probe 1 can also be used for the detection of hydrazine in HeLa cells and does so without appreciable interference from other biologically abundant amines and metal ions.U.S. National Science Foundation CHE-1057904Robert A. Welch Foundation F-1018CRI project grant from National Research Foundation of Korea (NRF)Korea government (MSIP) 2009-0081566Chemistr

Method of making MOS transistor having improved oxynitride dielectric

High quality ultrathin gate oxides having nitrogen atoms therein with a profile having a peak at the silicon oxide-silicon interface are formed by oxidizing a surface of a monocrystalline silicon body in an atmosphere of nitrous oxide (N.sub.2 O) at a temperature above 900.degree. C. preferably in the range of 900.degree.-1100.degree. C., and then heating the silicon body and oxidized surface in an atmosphere of anhydrous ammonia to introduce additional nitrogen atoms into the oxide and increase resistance to boron penetration without degrading the oxide by charge trapping. The resulting oxynitride has less degradation under channel hot electron stress and approximately one order of magnitude longer lifetime than that of conventional silicon oxide in MIS applications.Board of Regents, University of Texas Syste

Exploring the nexus between obesity, metabolic syndrome, and colorectal cancer

The increasing global prevalence of obesity and metabolic syndrome (MetS) is strongly associated with the incidence of colorectal cancer (CRC). Obesity and MetS detrimentally impact the treatment outcomes of CRC and share similar mechanisms that contribute to the development of CRC. Increased insulin resistance in patients with obesity is linked to CRC, and altered levels of sex hormones and adipokines affect cell growth and inflammation. Obesity and MetS also alter the gut microbiome. Bile acids, which are crucial for lipid metabolism, are elevated in patients with obesity. Moreover, specific bile acids are associated with colonic damage, inflammation, and the development of CRC. Obesity and MetS increase the risk of postoperative complications and affect the response to chemotherapy. The promotion of weight loss and the resolution of MetS can reduce the occurrence of CRC and increase treatment efficacy. Therefore, it is imperative to implement appropriate management strategies to address obesity and MetS with the aim of improving the prognosis and reducing the incidence of CRC. Moreover, additional research should be conducted to determine the optimal timing for tailored CRC screening in patients with obesity or MetS. In this review, we explore the impact of obesity and MetS on the development of CRC and examine potential strategies to mitigate CRC risk in individuals with obesity and MetS

Direct growth of nickel disilicide nanocrystals in silicon dioxide films

Nickel disilicide (NiS₂)nanocrystals (NCs) have been grown in silicon-rich oxide (SiOₓ)films ion implanted with nickel by annealing at 1100°C. It was found that NiS₂ NCs grew into well-defined single crystalline structures embedded in a SiOₓ matrix and were approximately spherical in shape. The size of NCs can be influenced by limiting either the Ni or excess Si concentration. It was found that the resulting NCs could be produced with diameters in the range from 5to40nm in the SiOₓ layers with excess Si concentrations of 4–8at.% implanted with Ni concentrations of 0.1–10at.%.This work was carried out under Scientists Exchange Program between the Korea Science and Engineering Foundation and the Australian Academy of Science, and supported by the Research Grant from the Kangwon National University